Antibody-modified magnetic nanoparticles as specific high-efficient cell-separation agents.

Separation of tumor cells is a promising approach that helps not only in early detection of cancer but also as an efficient tool that holds great importance in prohibiting cancer cell mutation, drug resistance to treatments, and in granting successful adjuvant therapies. As one of the highly efficient processes for the separation of single cells, tumor cells, and specific proteins from fresh whole blood, a magnetic iron oxide nanoparticle (IONP)-based immunomagnetic separation technique has been developed in this article. The synthesized IONPs were modified with antibodies (Abs) against human epithelial growth factor receptor 2 (HER2), which is overexpressed and/or amplified in about 15% of breast cancer patients with several types of human cancer cells. The prepared Ab-conjugated IONPs (Ab-IONPs) attach HER2-positive cancer cells exclusively and can serve as specific high-efficient single-cell separation agents. The results showed that the magnetic IONPs have been successfully attached to the Abs via 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide/N-hydroxysuccinimide linkers. Maximum targeting efficiency of the Ab-IONP complex, which was 94.5 +/- 0.8% for BT474 and 70.6 +/- 0.4% for mixture of cells (BT474 and MCF7), was achieved with a minimum amount of Abs, to provide an economically efficient single-cell detection device.